What about it? You can see their sources at the bottom.
Wikipedia is actually pretty reliable; they have little to no bias, and when a new user edits something, it is transferred to the mods there to review before it is actually implemented. Other pages with more security often don't allow new users to edit at all! That's why vandalism (on wikipedia) has lessened considerably now compared to before. And if there is an edit without a source, then it'd write some like [source?] in superscript.